Coaxial cables usually comprise a core (or center conductor member coated with a dielectric), with an outer conductor member coaxially superimposed on the dielectric. The center conductor member and the outer conductor member are made with some appropriate metal, e.g. copper, aluminum and appropriate alloys of same, and the dielectric is usually composed of some suitable plastic, e.g. polyethylene, polystyrene, polypropylene. The dielectric can either be in the expanded (foam) or unexpanded (solid) form.